performance/stat-prefetch: remove lock member in sp_fd_ctx_t.

- since the lifetime of fd context can be no longer than the fd, we can use
    lock in fd.

Signed-off-by: Raghavendra G <raghavendra@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 405 (Segmentation fault in stat-prefetch.)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=405

2 files changed, 22 insertions, 36 deletions

diff --git a/xlators/performance/stat-prefetch/src/stat-prefetch.c b/xlators/performance/stat-prefetch/src/stat-prefetch.c
index 75a74b531..73fac4c7c 100644
--- a/xlators/performance/stat-prefetch/src/stat-prefetch.c
+++ b/xlators/performance/stat-prefetch/src/stat-prefetch.c
@@ -250,11 +250,7 @@ __sp_get_cache_fd (xlator_t *this, fd_t *fd)
 
         fd_ctx = (void *)(long) value;
 
-        LOCK (&fd_ctx->lock);
-        {
-                        cache = fd_ctx->cache;
-        }
-        UNLOCK (&fd_ctx->lock);
+        cache = fd_ctx->cache;
 
 out:
         return cache;
@@ -314,9 +310,6 @@ sp_fd_ctx_init (void)
         sp_fd_ctx_t *fd_ctx = NULL;
 
         fd_ctx = CALLOC (1, sizeof (*fd_ctx));
-        if (fd_ctx) {
-                LOCK_INIT (&fd_ctx->lock);
-        }
 
         return fd_ctx;
 }
@@ -364,19 +357,16 @@ sp_del_cache_fd (xlator_t *this, fd_t *fd)
                 goto out;
         }
 
-        ret = fd_ctx_get (fd, this, &value);
-        if (ret == -1) {
-                goto out;
-        }
-
-        fd_ctx = (void *)(long) value;
-
-        LOCK (&fd_ctx->lock);
+        LOCK (&fd->lock);
         {
-                cache = fd_ctx->cache;
-                fd_ctx->cache = NULL;
+                ret = __fd_ctx_get (fd, this, &value);
+                if (ret == 0) {
+                        fd_ctx = (void *)(long) value;
+                        cache = fd_ctx->cache;
+                        fd_ctx->cache = NULL;
+                }
         }
-        UNLOCK (&fd_ctx->lock);
+        UNLOCK (&fd->lock);
 
 out:
         return cache;
@@ -431,15 +421,11 @@ __sp_put_cache (xlator_t *this, fd_t *fd, sp_cache_t *cache)
                 }
         }
 
-        LOCK (&fd_ctx->lock);
-        { 
-                if (fd_ctx->cache) {
-                        sp_cache_free (fd_ctx->cache);
-                }
-
-                fd_ctx->cache = cache;
+        if (fd_ctx->cache) {
+                sp_cache_free (fd_ctx->cache);
         }
-        UNLOCK (&fd_ctx->lock);
+
+        fd_ctx->cache = cache;
 
 out:
         return ret;
diff --git a/xlators/performance/stat-prefetch/src/stat-prefetch.h b/xlators/performance/stat-prefetch/src/stat-prefetch.h
index 3ea163b2c..0e9353303 100644
--- a/xlators/performance/stat-prefetch/src/stat-prefetch.h
+++ b/xlators/performance/stat-prefetch/src/stat-prefetch.h
@@ -37,25 +37,25 @@
 
 struct sp_cache {
         rbthash_table_t *table;
-        uint64_t    expected_offset;    /* Offset where the next read will
-                                         * happen.
-                                         */
-        gf_lock_t   lock;
-        unsigned long miss;
-        unsigned long hits;
+        uint64_t         expected_offset;    /* Offset where the next read will
+                                              * happen.
+                                              */
+        gf_lock_t        lock;
+        unsigned long    miss;
+        unsigned long    hits;
+        uint32_t         ref;
 };
 typedef struct sp_cache sp_cache_t;
 
 struct sp_fd_ctx {
         sp_cache_t *cache;
-        inode_t    *parent_inode;       /* 
+        inode_t    *parent_inode;       /*
                                          * inode corresponding to dirname (path)
                                          */
         char       *name;               /*
-                                         * basename of path on which this fd is 
+                                         * basename of path on which this fd is
                                          * opened
                                          */
-        gf_lock_t    lock;
 };
 typedef struct sp_fd_ctx sp_fd_ctx_t;